Synthesis of the racemic alkaloid diptaline

The isolation from the plantDipthychocarpus strictus (Cruciferae) of the optically active base diptaline, identified as N-(11-methylsulfinylundecyl)urea, has been reported [1]. A synthesis of the racemic form of this alkaloid has now been achieved.Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 102–105, January–February, 1992.     

Negative-ion mass spectra of the synthetic alkaloid diptocarpilidine and its deoxy precursor

The existence of the molecules of the synthetic alkaloid diptocarpilidine in a folded conformation as a consequence of the intramolecular interaction of the sulfoxide and cyano groups through space has been established by negative-ion mass spectrometry.Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 543–546, September–October, 1992.     

Negative-ion mass spectra of the synthetic alkaloid diptocarpilidine and its deoxy precursor

The existence of the molecules of the synthetic alkaloid diptocarpilidine in a folded conformation as a consequence of the intramolecular interaction of the sulfoxide and cyano groups through space has been established by negative-ion mass spectrometry. Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 543–546, September–October, 1992.     

Total synthesis of the racemic alkaloid diptocarpamine

A route for the synthesis of racemic diptocarpamine from hex-5-enoic acid has been developed.Institute of Chemistry, Bashkir Scientific Center of the Urals Branch, USSR Academy of Sciences, Ufa. Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 232–236, March–April, 1989.     

Structure of diptocarpilidine

Diptocarpilidine (bp 193–194° (4 mm)) has been isolated from the epigeal part and seeds ofDiptychocarpus strictus (Fisch) Trautv., and its structure has been established as 1-cyano-6-methylsulfinylhexane.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 84–86, January–February, 1984.     

Synthesis of racemic erythro-dihydrosphingosine

Conclusions Racemic erythro-dihydrosphingosine was synthesized by hydroxymethylation and cleavage of 4-palmityl-5-oxazolinone with subsequent reduction and saponification of the intermediate 1-hydroxy-2-benzamido-3-octadecanone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1445–1446, June, 1972.We sincerely thank R. P. Evstigneeva and E. N. Zvonkova for furnishing us with a sample of VII.     

Synthesis of the isoindolobenzazepine alkaloid lennoxamine

The naturally occurring isoindolobenzazepine lennoxamine (1) has been synthesised from 6-bromopiperonal in 9 steps by a route which involves formation of the 2-arylbenzazepine (10) from the azide (9) as the key step.     

Synthesis of the marine alkaloid caulersin

A three-step synthesis of caulersin (3) from indole-2-acetic acid methyl ester and indole-2-carbonyl chloride is described. As the spectral data of the synthetic sample differed from those reported for the natural product, the structure was determined by X-ray crystallography.     

Synthesis of the spirocyclic alkaloid nitramine

The alkaloid nitramine was prepared in a four operation process using reductive cyclization of a γ-cyano ester to a spirolactam as a key step.     

Synthesis of N-aminoglycosides of the alkaloid cytisine

A series of new N-aminoglycosides of the alkaloid cytisine based on industrially available monosaccharides D-glucose, D-galactose, D-xylose, and L-arabinose was synthesized and characterized. The optimal methods for condensing and isolating the products were found. The structures and position of cytisine in the glycosides were proved by PMR spectroscopy. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 596–597, November–December, 2008.     

Synthesis of the racemic sex pheromone of Pseudococcus comstocki

The synthesis of the acetate of 2,6-dimethylhepta-1,5-dien-3-ol — the sex pheromone of the Comstock bug — has been carried out by condensing isobutenyllithium with 3,4-epoxy-2-methylbut-1-ene and acetylating the 2,6-dimethylhepta-1,5-dien-3-ol formed. The overall yield of pheromone was 46%.N. D. Zelinski Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow. All-Union Scientific-Research Institute of Biological Methods of Plant Protection, Kishinev. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 132–134, January–February, 1989.     

Synthesis of the Arctic sponge alkaloid viscosaline and the marine sponge alkaloid theonelladin C

The synthesis of Arctic sponge alkaloid viscosaline (1) is achieved by using the Zincke reaction as the penultimate step. A key synthetic intermediate theonelladin C (6), itself a marine sponge natural product, is synthesised efficiently using a four-step sequence.